Evaluation of interactions between food colorant, tartrazine, and Apo-transferrin using spectroscopic analysis and docking simulation

Colors are one of the most widely used additives in the food industry. Despite the fact that tartrazine, which is an artificial synthetic acid azo dye, has frequently been used worldwide, it has recently been prohibited to be used in many countries including. The tartrazine occurrence was investigated in Iranian cooked rice and confectioneries by HPLC-DAD. The interaction between transferrin and tartrazine was studied using different spectroscopic and simulation methods. Of the total sixty samples, nine samples (15%) were positive for the tartrazine. The emission intensity of transferrin was quenched by tartrazine, and the process behind the quenching was static. The thermodynamic parameters obtained from the analysis of tryptophan and tyrosine fluorescence revealed spontaneous interactions between tartrazine and Apo-transferrin. Finally, in tartrazine-transferrin interactions, hydrogen bond and van der Waals forces most certainly played seminal roles. The MD and CD results revealed that the interaction of tartrazine/transferrin can influence the secondary and tertiary structure of protein. This color used in the food industry is based on the findings reported and can bind substantially to Apo-transferrin, further verified by molecular docking analysis.